Mrs. Arafat, estranged from most of the Palestinian leadership, followed the exhumation from her home in Malta, according to a local newspaper. Mrs. Arafat, who did not consent to an autopsy immediately after her husband's death, told The Times of Malta that her husband's death was the "most important mystery in the Middle East."
Arafat died a month after falling ill at his West Bank compound. The immediate cause of death was a stroke, but the underlying reasons remain unclear, leading to widespread belief in the Arab world that Israel poisoned him.
Medical files released by Palestinian investigators earlier this year portrayed Arafat as a robust 75-year-old whose sudden health crisis was initially blamed on viral gastroenteritis.
Arafat's downward spiral began Oct. 11, 2004, when he vomited after a late supper. His condition deteriorated and two weeks later he was flown to France where he died Nov. 11, 2004.
Dr. Bashir Abdullah, a physician on the Palestinian team of investigators, said Tuesday that Arafat's death "cannot be explained in the framework of disease, and therefore our explanation is that there must have been poisonous material."
Palestinian officials acknowledged Tuesday that they had a long road ahead and that the investigation could hit a dead end.
Tawfik Tirawi, the head of the Palestinian team, said the Palestinians would ask the International Criminal Court to investigate further if there is evidence of poisoning.
Later this week, Abbas is seeking U.N. recognition of "Palestine" as a non-member observer state, an upgrade that could give Palestinians access to the ICC.
Tirawi said previous calls by some high-ranking Israeli officials to get rid of Arafat were an indication that Israel was involved, adding, "we are looking for the evidence."
Former Sharon aides have argued that Israel had no reason to kill Arafat since it had already pushed him aside by confining him to his compound.
For decades, Arafat was the symbol of the Palestinians' struggle for an independent state.
After returning from exile to the Palestinian territories in 1994, as part of interim peace deals with Israel, he zigzagged between leading negotiations with Israel and condoning violence.
Arafat, along with two Israeli leaders, received the Nobel Peace Prize for his commitment to work toward peace with Israel.
He later presided over a violent Palestinian uprising against Israel's occupation of the West Bank, Gaza and east Jerusalem, the territories they seek for a state. As the uprising escalated, Israel confined him to his Ramallah compound.
Arafat also faced criticism at home, where some accused his political circle of corruption and the pocketing of large amounts of aid. But he remains a widely revered figure, and his portrait frequently appears in government offices and street posters.
Associated Press writers Tia Goldenberg in Jerusalem and Dalia Nammari in Ramallah contributed reporting.